1. Technical Field
The present invention pertains to the field of convertible seats, and more specifically, to convertible seats that provide a comfortable lying surface for a user.
2. Background of the Invention
Seating units (e.g., sofas, chairs, etc.) that are convertible into beds are popular with consumers because of their multi-functionality. Many consumers find it very convenient to have a seating unit that can provide a bed for a guest; as such a unit can eliminate the need for an additional, separate bed. Some such seating unit designs include their own complete mattress that is folded within a cavity of the sofa or chair during periods of non-use. This type of sofa-bed can be quite heavy, and typically requires not only a separate mattress, but also a relatively intricate mechanism to control the unfolding and folding of the mattress.
Other sofa-beds lack a complete mattress, but instead are constructed of separate sections that serve as support surfaces of the sofa or chair and unfold to form a flat, mattress-like lying/sleeping surface. Such a sofa-bed includes a backrest, a seat and a “subseat” that unfold to form a horizontal lying surface. In the folded “chair” configuration, the backrest is generally upright, and the seat and “subseat” fold upon each other (with the subseat in an inverted position). The backrest is guided between positions by preformed slots in the arms of the sofa that receive posts that extend laterally from the backrest. The backrest is coupled to the seat and subseat via an angled link. The subseat is pivotally attached at one end to the arms and is hinged at the other end to the seat.
Convertible beds are popular in health care environments (e.g., hospitals), because they provide a family member visiting a patient with a furniture piece in the patient's room on which one can sit, lie down on, or sleep. Because hospital rooms are typically short on available space, convertible beds used in hospital rooms are typically the width of a chair. Such beds may also be used in recreational vehicles. Generally speaking, such beds are designed with compactness and ease of conversion as their primary features, with little to no regard for the comfort of the user. An example of such configuration is illustrated in FIGS. 1A and 1B. FIG. 1A is a perspective view of a convertible chair 10 shown in the folded or chair configuration. FIG. 1B is a side section view of the convertible chair 10 shown in the unfolded (i.e., bed) configuration.